The correct amount of planning

In a very general sense, there is no “right” amount of planning or organizing
you can do prior to starting a project. However, by identifying what “too
little” and “too much” are, you can hope to find something that works.

On the “too much” end of the spectrum:

Speculating about situations that may or may not ever arise far down the road
is usually a waste of time. Better to dig in and start creating.

Drafting a 100 page design document that multiple parties sign off on is
usually a waste of time. People are generally thinking of slightly different
things when they read about functionality—over the course of a large document
these differences add up.

On the “too little” end:

Don’t just start work on a project without covering at least a few general
questions. What’s the goal? How can it be accomplished? What might cause it to
fail and how can we avoid those things? How will it make money?

Avoid “hand waving” issues away. For example, if you don’t have widget X in
place yet and the person building widget Y needs X before they can begin,
don’t use “X is available” as an assumption in the project timeline. A lot of
“hand waving” will lead to a group of people who can all claim to not be
responsible for a failed project.